Vibrating gyroscope

ABSTRACT

A vibrating gyroscope includes a vibrator having a node and a support member having a thin flexible portion and an expanded portion which is connected to the thin flexibly portion and has a larger area than the thin flexible portion. The expanded portion of the support member is fixed to the vibrator at the node.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a vibrating gyroscope, and moreparticularly to a vibrating gyroscope used in a video camera or the liketo detect external vibrations such as hand shaking by detecting arotational angular velocity and cancel out the vibrations on the basisof the detected information.

[0003] 2. Description of the Related Art

[0004] One type of vibrating gyroscope is disclosed in JapaneseLaid-open Patent Publication No. 8-278145, which is described below withreference to FIG. 1. As shown in FIG. 1, the vibrating gyroscope 1comprises a vibrator 2 made of a rectangular shaped piezoelectricceramic material, and two support members 3 having a circular columnarshape and being made of silicone-based resin material.

[0005] The vibrator 2 is fixed to a substrate 4 via the support members3 in such a manner that one end face of each support member 3 isconnected to a respective one of two nodes N which occur when thevibrator 2 vibrates and the other end face of each support member 2 isconnected to the base plate 4.

[0006] Japanese Laid-open Patent Publication No. 8-278145 furtherdiscloses that the support members 3 are also formed into a rectangularshape instead of the circular columnar shape.

[0007] The vibrating gyroscope according to the conventional techniquehas the following problems.

[0008] In the conventional vibrating gyroscope in which the vibrator issupported on the support members in the form of columns, the diameter ofthe columns should be large enough to stably support the vibrator.However, the large diameter of the columns can cause the vibration ofthe vibrator to leak to the substrate through the support members. As aresult, a reduction occurs in the amplitude of the vibration of thevibrator. The magnitude of a signal detected by the vibrating gyroscopevaries in proportion to the amplitude of the vibrator, and thus themagnitude of the detected signal decreases with the reduction in theamplitude of the vibration of the vibrator. Therefore, the vibratinggyroscope of such a type has a rather low sensitivity.

[0009] It is therefore an object of the present invention to solve theabove problems. More specifically, it is an object of the presentinvention to provide a vibrating gyroscope in which a vibrator issupported in a stable fashion without causing a significant reduction inthe sensitivity thereby achieving a high sensitivity.

SUMMARY OF THE INVENTION

[0010] According to a preferred embodiment of the present invention, avibrating gyroscope comprises a vibrator having at least one node, and asupport member having a thin flexible portion and an expanded portionwhich is connected the thin flexible portion and has a larger area thanthe thin flexible portion. The expanded portion of the support member isfixed to the vibrator at the at least one node.

[0011] The expanded portion may have a through-hole therein.

[0012] According to another embodiment of the present invention, avibrating gyroscope comprises a vibrator having at least a first node,and first and second support members supporting the vibrator such thatthe first and second support members sandwich the at least first node ofthe vibrator.

[0013] The vibrator in either embodiment may comprise first and secondpiezoelectric substrates stacked with each other and being polarized inopposite directions of their thickness directions; first and secondsplit electrodes formed on a principal surface of the firstpiezoelectric substrate; and a common electrode formed on a principalsurface of the second piezoelectric substrate.

[0014] The vibrating gyroscope may further comprise third and fourthsupport members, and the vibrator may have a second node. The third andfourth support members support the vibrator such that the third andfourth support members sandwich the second node of the vibrator. Each ofthe first, second third and fourth support members may have a thinflexible portion and an expanded portion which is connected to the thinflexible portion and has a larger area than the thin flexible portion,and each of the first, second third and fourth support members may befixed to the vibrator at the expanded portion thereof.

[0015] One of the first and second support members may be electricallyconnected to the first split electrode and one of the third and fourthsupport members may be electrically connected to the second splitelectrode.

[0016] According to the vibrating gyroscope of the preferred embodimentof the invention, the contact area between the vibrator and the supportmembers is large enough so that the vibrator is firmly supported by thesupport members thus achieving high resistance to shock. Other than theconnecting portion, the support member is thin and flexible so that thesupport member has little influence on the vibration of the vibrator,thus not preventing the free vibration of the vibrator and therebyensuring that the vibrator vibrates with a large enough amplitude toprovide a large output signal so that the vibrating gyroscope has a highsensitivity.

[0017] Further, the vibrator is supported by being vertically clamped ina sandwich fashion by support members; hence, a problem in which theportions where the vibrator and the support members are bonded aredamaged when the vibrator oscillates and the vibrator eventuallydetaches and falls will not arise, enabling the support structure toprovide improved impact resistance and stable joint states.

[0018] Moreover, since the support members hold the vibratortherebetween, the support members are not particularly required to haveany substantial height, so that the support structure may be madeshorter, permitting the entire apparatus to be made shorter accordingly.

[0019] For the purpose of illustrating the invention, there is shown inthe drawings several forms which are presently preferred, it beingunderstood, however, that the invention is not limited to the precisearrangements and instrumentalities shown.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a perspective view showing a structure of a conventionalvibrating gyroscope.

[0021]FIG. 2 is a perspective view showing a structure of a vibratinggyroscope according to a first embodiment of the present invention.

[0022]FIG. 3 is a schematic circuit diagram for operating the vibratinggyroscope shown in FIG. 2.

[0023]FIG. 4 is perspective view showing a structure of a vibratinggyroscope according to a second embodiment of the present invention.

[0024]FIG. 5 is a perspective view showing the vibrating gyroscope ofFIG. 4 mounted in a frame.

[0025]FIG. 6 is a perspective view showing a structure of a vibratinggyroscope according to a variation of the second embodiment of thepresent invention.

[0026]FIG. 7 is a perspective view showing a structure of a vibratinggyroscope according to a third embodiment of the present invention.

[0027]FIG. 8 is a perspective view showing the vibrating gyroscope ofFIG. 7 mounted in a frame.

[0028]FIG. 9 is a perspective view showing a structure of a vibratinggyroscope according to a variation of the third embodiment of thepresent invention.

[0029]FIG. 10 is a perspective view showing a structure of a vibratinggyroscope according to another variation of the third embodiment of thepresent invention.

[0030]FIG. 11 is a perspective view showing a structure of a vibratinggyroscope according to a fourth embodiment of the present invention.

[0031]FIG. 12 is a perspective view showing the vibrating gyroscope ofFIG. 11 mounted in a frame.

[0032]FIG. 13 is a perspective view showing a structure of a vibratinggyroscope according to a variation of the fourth embodiment of thepresent invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0033] Hereinafter, the preferred embodiments of the present inventionare explained in detail with reference to the drawings.

[0034] First Embodiment

[0035]FIG. 2 illustrates a first embodiment of a vibrating gyroscopeaccording to the present invention. As shown in FIG. 2, a vibratinggyroscope 10 comprises a vibrator 11 having a substantially rectangularprism shape and four support members 12. The support members 12 supportthe vibrator 11 at positions corresponding to the two vibration nodes N1and N2 which appear when the vibrator 11 vibrates.

[0036] The vibrator 11 comprises a first piezoelectric substrate 13, asecond piezoelectric substrate 14 and an electrode layer 15, the firstpiezoelectric substrate 13 and the second piezoelectric substrate 14sandwiching the electrode layer 15. The first and second piezoelectricsubstrates 13 and 14 are polarized in opposite directions along thedirection of their thickness as represented by arrows in FIG. 2. It isnoted that the piezoelectric substrates 13 and 14 may be polarized inthe same direction in the case where the vibrating gyroscope is operatedwith the electrode layer grounded.

[0037] On the principal surface of the first piezoelectric substrate 13,that is, the surface of the first piezoelectric substrate 13 opposite tothe surface in contact with the electrode layer 15, there are splitelectrodes 16 a and 16 b spaced from each other in a directionperpendicular to the longitudinal direction. The split electrodes 16 aand 16 b are each also divided along the longitudinal direction of thevibrator 11 at positions shifted outward from the vibration nodes N1 andN2 of the vibrator 11 toward the ends in the longitudinal direction ofthe vibrator 11, thereby dividing the split electrodes 16 a and 16 binto a pair of outer divided electrodes and a central divided electrode,respectively. There is provided a common electrode 17 on the principalsurface of the second piezoelectric substrate 14, that is, the surfaceof the second piezoelectric substrate 14 opposite to the surface incontact with the electrode layer 15.

[0038] Each of the four support members 12 is made of a thin metal plateand has a thin flexible portion in a wire form and an expanded portionhaving a larger area than the thin flexible portion. More specifically,each support member 12 has a Z shaped bent portion as a thin flexibleportion and an expanded portion 18 at one end of the Z-shaped bentportion. The Z shaped bent portion is a thin plate having a narrowwidth. The expanded portion 18 extends in the direction perpendicular tothe direction in which the bent portion extends so as to have a largerarea than that of the bent portion. FIG. 2 shows that the expandedportion 18 has a rectangular shape. The expanded portions 18 of the foursupport members 12 are fixed to the central divided electrodes of thesplit electrode 16 a and 16 b by means of soldering or the like so thatone end of each support member 12 extends in the direction perpendicularto the longitudinal direction of the vibrator 11 and that the connectionpositions correspond to the two vibration nodes N1 and N2, respectively,which appear when the vibrator 11 vibrates.

[0039]FIG. 3 illustrates an electric circuit connected to the vibratinggyroscope 10. The split electrodes 16 a and 16 b are connected, viaresistors 22 a and 22 b, respectively, to one output terminal of anoscillator 21 serving as driver means. The common electrode 17 isconnected to the other terminal of the oscillator 21. The splitelectrodes 16 a and 16 b are also connected, via resistors 23 a and 23b, respectively, to a noninverting input terminal (+) and an invertingterminal (−) of a differential amplifier 25 serving as detector means.The output of the differential amplifier 24 is connected, via a resistor25, to the inverting input (−) of the differential amplifier 24.

[0040] In the case where a driving signal in the form of, for example, asine wave generated by the oscillator 21 is applied via the resistors 22a and 22 b to the split electrodes 16 a and 16 b of the vibrator 11, thefirst piezoelectric substrate 13 and the second piezoelectric substrate14 vibrate in a direction perpendicular to the principal surfaces of therespective piezoelectric substrates under a bending mode. When thevibrating gyroscope 10 rotates about the center line O of the vibrator11, a Coriolis force is generated depending on the rotational angularvelocity, wherein the Coriolis force is generated in a directionparallel to the principal surface of the first and second piezoelectricsubstrates 13 and 14 and perpendicular to the center axis O of thevibrator 11. The Coriolis force causes a change in the direction of thebending vibration of the vibrator 11, which results in generation of asignal between the split electrodes 16 a and 16 b depending on therotational angular velocity. The signal generated between the splitelectrodes 16 a and 16 b is detected via the resistors 23 a and 23 b bythe differential amplifier 24. Thus the angular velocity of the rotationcan be detected from the output signal of the differential amplifier 24.

[0041] In the vibrating gyroscope 10, the contact area between thevibrator 11 and the support members 12 is large enough so that thevibrator 11 is firmly supported by the support members 12, thusachieving high resistance to shock. Other than the expanded portion 18,each support member 12 is formed into a thin plate shape so that novibration is substantially transmitted from the vibrator 11 to theoutside of the vibrator 11 through the support members 12, and thus novibration damping occurs, thereby ensuring that the vibrator 11 vibrateswith a large enough amplitude so that the vibrating gyroscope 10 has ahigh sensitivity.

[0042] In addition, since each support member has a Z-shape bentportion, it is possible for the support member 12 to absorb the impactapplied to the vibrator 11 along either x, y or z axis.

[0043] Second Embodiment

[0044]FIG. 4 illustrates a second embodiment of a vibrating gyroscopeaccording to the present invention. In the vibrating gyroscope 30, avibrator 11 is supported by two support members 32 which are connectedto the common electrode 17 at two vibration nodes N1 and N2 and whichextend from the vibrator 11 in directions perpendicular to thelongitudinal direction thereof.

[0045] Each support member 32 has a pair of Z-shaped bent portions as athin flexible portion and an expanded portion 38 in a substantiallycircular shape. The pair of Z-shaped bent portions are symmetricallyconnected to the expanded portion 38 so as to extend in the oppositedirections. The expanded portions 38 of the support members 32 arerespectively fixed at the nodes N1 and N2 so that each support member 32has a larger contact area at the expanded portion 38 and that both endsof each support member 32 extend in a direction perpendicular to thelongitudinal direction of the vibrator 11. The other parts of thevibrating gyroscope 30 are similar to those of the vibrating gyroscope10 and denoted with the same reference numerals. Also, the vibratinggyroscope 30 is operated using the circuit shown in FIG. 2.

[0046] In this vibrating gyroscope 30, the vibrator is supported by onlytwo support members in a simpler fashion than the first embodiment ofthe vibrating gyroscope.

[0047] The vibrating gyroscope 30 can be successfully mounted to a frameshaped support. As shown in FIG. 5, the vibrator 11 is placed in a metalframe 61 in such a manner that the vibrator 11 is suspended from thesupport members 32. The support members 32 are firmly connected to theupper end face of the frame 61 by means of soldering or the like so thatthe vibrator 11 is suspended in the hollow space within the frame and sothat the plane of the common electrode 17 of the vibrator 11 is flushwith the upper end face of the frame 61.

[0048] By employing the above technique of mounting the vibratinggyroscope, it becomes possible to realize a vibrating gyroscope having asmall total height. The reduction in the total height brings about anincrease in the flexibility in the design of the vibrating gyroscope.Because the plane of the common electrode 17 of the vibrator 11 is flushwith the upper end face of the frame 61, it is possible tosimultaneously solder a plurality of connections. This allows theassembling process to be performed in a highly efficient fashion usingan automated assembling machine having a simple structure.

[0049] In the first and second embodiment, although each support memberis formed into a Z-shape, the shape of the support members is notlimited to an acute-angled shape such as a Z-shape, but may also have acurved shape. Furthermore, the support members may be formed either in abent shape or in a non-bent shape. However, a bent shape brings aboutthe advantage that the vibrator can be elastically supported so thatwhen the vibrator vibrates, the support members are deformed at the bentportions of the support members thereby suppressing the vibrationdamping.

[0050] Furthermore, although metal is employed as the material of thesupport members in the above embodiments, the material is not limited tometal. However, the employment of metal having the elastic propertyenables the support members to be easily bent to suppress vibrationdamping. Furthermore, when the support members are made of metal, thesupport members may also be used as lead wires. In this case, noadditional lead wires are necessary, and thus the production processbecomes simpler and the elimination of the additional lead wiresextending through the hollow space make the structure of the vibratinggyroscope simpler.

[0051] Furthermore, the shape of the expanded portions of the supportmembers is not limited to either a circular shape or a rectangularshape, but an arbitrary shape may be employed depending on theparticular application in which the vibrating gyroscope is used ordepending on the shape of the vibrator.

[0052] Although in the above embodiments the vibrator comprises twopiezoelectric substrates, there is no particular limitation in terms ofthe structure of the vibrator, and the present invention may also beapplied to a vibrator made of metal pieces in the form of a triangularor rectangular prism.

[0053]FIG. 6 illustrates a variation of the second embodiment of avibrating gyroscope according to the present invention. In thisvibrating gyroscope 50, two support members 52 are connected to thecommon electrode 17 of the vibrator 11 in such a manner that theconnection positions correspond to two vibration nodes N1 and N2. Eachof the support member 52 has the same shape as that of the supportmember 32 shown in FIG. 4 except that an expanded portion 58 has athrough-hole 59 formed in its central position. The other parts of thevibrating gyroscope 50 are similar to those of the vibrating gyroscope30 and denoted by similar reference numerals.

[0054] In this vibrating gyroscope 50 having the above-describedstructure, when the support members 52 are connected to the vibrator 11via solder, solder may be placed in the throughhole 59 of each supportmember 52. This allows the amount of solder connecting the vibrator 11to the support members 52 to be controlled more easily at a desiredfixed value without producing an excess or lack of solder than thevibrating gyroscope according to the embodiments of FIG. 2 or FIG. 5.Furthermore, the soldering position can be precisely controlled becausethe soldering position is determined by the position of the through-hole59 which can be precisely formed at a fixed position. Thus it ispossible to realize a vibrating gyroscope having a supporting mechanismcapable of providing a high reliability connection.

[0055] Third Embodiment

[0056]FIG. 7 illustrates a third embodiment of a vibrating gyroscopeaccording to the present invention. A vibrating gyroscope 60 comprises arectangular prism shaped vibrator 11 and support members 12 a, 12 b, 12c, 12 d, 12 e, and 12 f which support the vibrator 11 such that thesupport members 12 a, 12 b, 12 c, 12 c, 12 d, 12 e, and 12 f clamp thevibrator 11 at the points corresponding to two nodes N1 and N2. Thevibrator 11 has the same structure as that explained in detail withreference to FIG. 2.

[0057] The support members 12 a, 12 b, 12 d, and 12 e include respectiveZ-shaped bent portions and respective expanded portions 18 a, 18 b, 18d, and 18 e and have the same structure as that of the support members12 (FIG. 1) explained in the first embodiment. On the other hand, thesupport members 12 c and 12 f include a pair of Z-shaped bent portionsand expanded portions 18 c and 18 f and have the same structure as thatof the support members 32 (FIG. 4) explained in the second embodiment.

[0058] The support members 12 a and 12 b are secured, via the expandedportions 18 a and 18 b, by soldering or the like to the segmentalelectrodes 16 a and 16 b located on the top of the vibrator 11 at thenode N1. The support member 12 c is secured, via the expanded portion 18c, by soldering or the like to the common electrode 17 located on thebottom of the vibrator 11 at the node N1. Likewise, the support members12 d and 12 e are secured, via the expanded portions 18 d and 18 e tothe segmental electrodes 16 a and 16 b located at the node N2. Thesupport member 12 f is secured, via the expanded portion 18 f, to thecommon electrode 17 located at the node N2.

[0059] Thus, the vibrator 11 is supported and secured by beingsandwiched vertically at the nodes N1 by support members 12 a, 12 b and12 c and at the nodes N2 by support members 12 d, 12 e and 12 f.

[0060] In the vibrating gyroscope 60, since the vibrator 11 is supportedby being sandwiched the possibility of the vibrator 11 detaching fromits supports is reduced and, thus, the vibrating gyroscope employing thesupport structure of this embodiment provides improved resistance toimpact and higher reliability.

[0061]FIG. 8 shows a vibrating gyroscope 60 mounted at a frame 61. Forthe purpose of clarity of illustration, the vibrator 11 is shown insimplified shape.

[0062] The vibrator 11 is suspended by the support members 12 a through12 f and put in a frame 61 made of metal or the like. The top surface ofthe frame 61 and the support members 12 a, 12 b, 12 d, and 12 f arebonded and secured by soldering or the like. In the same manner, thebottom surface of the frame 61 and the support members 12 c and 12 f arefixed. Thus, the vibrator 11 is supported and fixed in the hollow spacedefined by the frame 61. At this time, the top surface of the vibrator11 is flush with the top surface of the frame 61. Likewise, the bottomsurface of the vibrator 11 is flush with the bottom surface of the frame61.

[0063] The vibrating gyroscope installed as described above permits areduced height of the entire vibrating gyroscope, so that a shortervibrating gyroscope can be accomplished, and the reduced height alsoleads to greater freedom of design. In addition, since the top surfaceof the vibrator and the top surface of the frame are flush and thebottom surface of the vibrator and the bottom surface of the frame arealso flush, solder can be attached to a plurality of spots on the sameplane in the soldering process. This permits greater ease of work and,accordingly, allows an automated machine of a simpler structure to beintroduced in the assembly process.

[0064]FIG. 9 shows a variation of the vibrating gyroscope according tothe third embodiment of the present invention.

[0065] A vibrating gyroscope 70 shown in FIG. 9 is different from thevibrating gyroscope 60 shown in FIG. 7 in that the support member 12 band the support member 12 d are not mounted; in other words, there areonly four support members 12 a, 12 c, 12 e, and 12 f. The rest of theconfiguration is the same as that of the first embodiment; hence, likereference numerals will be used and the description thereof will beomitted.

[0066] The vibrator support structure configured as described above hasfewer support members, so that the configuration thereof is simplified.Moreover, since the number of contact points between the vibrator andthe support members is reduced, the vibration of the vibrator is notrestrained and, accordingly, becomes closer to free oscillation.Although the resistance to impact is lower than that of the vibratinggyroscope 60, it is sufficiently high for practical use owing to thesimpler sandwich structure.

[0067]FIG. 10 shows another variation of the vibrating gyroscopeaccording to the third embodiment of the present invention.

[0068] A vibrating gyroscope 80 is different from the vibratinggyroscope 60 shown in FIG. 7 in that the support member 12 d and thesupport member 12 e are not mounted; in other words, there are only foursupport members 12 a, 12 b, 12 c, and 12 f. The rest of theconfiguration is the same as that of the first embodiment; hence, likereference numerals will be used and the description thereof will beomitted.

[0069] The vibrator support structure configured as described above hasfewer support members, so that the configuration thereof is simplified.Moreover, since the number of contact points between the vibrator andthe support members is reduced, the oscillation of the vibrator is notrestrained and, accordingly, becomes closer to free oscillation.Although the resistance to impact is lower than that of the vibratinggyroscope 60, it is sufficiently high for practical use owing to thesandwich structure in one place at the node N1.

[0070] In this embodiment, the support members 12 a through 12 f havethe expanded portions 18 a through 18 f at the sections where thevibrator 11 is joined to the support members 12 a through 12 f. However,the present invention is not particularly limited to the structure wherethe areas of the joint portions of the support members are increased.Nevertheless, providing the expanded portion at the support members toincrease the joint areas adds to the force of the joint between thesupport members 12 a through 12 f and the vibrator 11, thus enablingsufficient resistance to impact to be obtained. The support members 12are shaped like thin lines other than the portions joined to thevibrator 11 in order to minimize the chance of the occurrence of avibrating damping problem caused by the leakage of the vibration of thevibrator 11 through support members 12 a through 12 f to the outside ofthe vibrator 11. Hence, the vibrating gyroscope has improved impactresistance and permits a sufficiently large vibration amplitude, so thatthe vibrating gyroscope provides better detection sensitivity.

[0071] Further, in this embodiment, the support members have the bentportions formed in a Z-shape. The support members, however, are notparticularly limited to have shapes with sharp bends like Z shapes; theymay alternatively be shaped to have curves. Further alternatively, thesupport members are not particularly required to have bends. Providingthe bends, however, makes it possible to resiliently support thevibrator; when the vibrator oscillates, the support members deform atthe curves so as to control the damping of the oscillation.

[0072] In addition, although the support members use metal as thematerial thereof in this embodiment, the material is not particularlylimited to metal. The use of a resilient metal for the support membersenables the support members to easily bend, so that the damping ofvibration can be further restrained. Moreover, constructing the supportmembers of metal allows the support members to serve also as lead wires,obviating the need for providing lead wires separately. This leads to asimplified process and also a simplified structure since there is nowiring structure of lead wires.

[0073] The invention has been described using a vibrator composed of twopiezoelectric substrates. However, the invention is not particularlylimited thereto, and the invention may be applied also to vibratorscomposed of triangular- or square-prism metal vibrating reeds.

[0074] Fourth Embodiment

[0075]FIG. 11 illustrates a vibrating gyroscope according to a fourthembodiment of the present invention. As shown in FIG. 11, a vibratinggyroscope 90 comprises a vibrator 11 having a substantially rectangularprism shape.

[0076] The vibrator 11 comprises a first piezoelectric substrate 13, asecond piezoelectric substrate 14 and an electrode layer 15, the firstpiezoelectric substrate 13 and the second piezoelectric substrate 14sandwiching the electrode layer 15. The first and second piezoelectricsubstrates 13 and 14 are polarized in opposite directions along thedirection of their thickness as represented by arrows in FIG. 11.

[0077] On one principal surface of the first piezoelectric substrate 13,that is, the surface of the first piezoelectric substrate 13 opposite tothe surface in contact with the electrode layer 15, there are providedsplit electrodes 16 a and 16 b spaced from each other in a directionperpendicular to the longitudinal direction of the first piezoelectricsubstrate 13 and extending along the longitudinal direction. There isprovided a common electrode 17 on one principal surface of the secondpiezoelectric substrate 14, that is, the surface of the secondpiezoelectric substrate 14 opposite to the surface in contact with theelectrode layer 15.

[0078] The split electrodes 16 a and 16 b have grooves S1, S2, S3 and S4along the direction perpendicular to the longitudinal direction suchthat the grooves S1 and S2 and the grooves S3 and S4 interpose thepositions corresponding to nodes N1 and N2 of the vibrator 11,respectively. As a result, the split electrode 16 a is divided intodivided electrodes 16 a-1, 16 a-2, 16 a-3, 16 a-4 and 16 a-5. In thesame manner, the split electrode 16 b is divided into divided electrodes16 b-1, 16 b-2, 16 b-3, 16 b-4 and 16 b-5.

[0079] The vibrating gyroscope 90 further comprises support members 98a, 98 b, 98 c and 98 d. The support members 98 a, 98 b, 98 c and 98 drespectively have a pair of Z-shaped bent portions and expanded portions99 a, 99 b, 99 c and 99 d in a rectangular shape. One end of each pairof Z-shaped bent portions is connected to the respective expandedportions 99 a, 99 b, 99 c and 99 d, whereby the expanded portions 99 a,99 b, 99 c and 99 d are located at the substantial middle of the supportmembers 98 a, 98 b, 98 c and 98 d, respectively. Each support member ismade of a permanent elastic metal such as elinvar, and is thereforeelectroconductive. The expanded portion of each support member is formedfor enlarging an area to be fixed to the vibrator 11 in each supportmember.

[0080] The expanded portion 99 a of the support member 98 a is fixed tothe divided electrodes 16 a-2 and 16 b-2 located at the node N1 throughsoldering, and the expanded portion 99 b of the support member 98 b isfixed to the divided electrodes 16 a-4 and 16 b-4 located at the node N2through soldering. On the other hand, the expanded portions 99 c and 99d of the support members 98 c and 98 d are fixed to portions of thecommon electrode 17 at the nodes N1 and N2 through soldering,respectively. It is preferable that the support members 98 a and 98 bare bent toward each other, and the support members 98 c and 98 d arebent away from each other as is shown in FIG. 11, or vice versa so thatthe vibrator 11 can be supported more stably. By this structure, thevibrator 11 is interposed or clamped between the support members 98 aand 98 c and the support members 98 c and 98 d and supported by thesupport members 98 a, 98 b, 98 c and 98 d.

[0081] In the gyroscope 90, the support member 98 a to 98 d are made ofmetal and used as conductive wires to be electrically connected to thedivided electrodes 16 a-3 and 16 b-3 and the common electrode 17. Morespecifically, the support member 98 a is to be used as an input/outputterminal for the divided electrode 16 a-3, and it is necessary for thesupport member 98 a to be electrically connected only with the dividedelectrode 16 a-3. Thus, the support member 98 a is provided with aprotrusion 98 a′ extending from the expanded portion 99 a toward thedivided electrode 16 a-3. The protrusion 98 a′ is electrically connectedto the divided electrode 16 a-3 through soldering or the like, wherebythe support member 98 a functions as a conductive wire for the dividedelectrode 16 a-3.

[0082] In the same manner, the support member 98 b is to be used as aninput/output terminal for the divided electrode 16 b-3, and it isnecessary for the support member 98 b to be electrically connected onlywith the divided electrode 16 b-3. Thus, the support member 98 b isprovided with a protrusion 98 b′ extending from the expanded portion 99b toward the divided electrode 16 b-3. The protrusion 98 b′ iselectrically connected to the divided electrode 16 b-3 through solderingor the like, whereby the support member 98 b functions as a conductivewire for the divided electrode 16 b-3.

[0083] It is noted that the support member 98 a is soldered to both thedivided electrodes 16 a-2 and 16 b-2. This means that the support member98 a is electrically connected to both the divided electrodes 16 a-2 and16 b-2 and that signals output from both the divided electrodes 16 a-2and 16 b-2 are detected though the support member 98 a. However, thisdoes not cause any substantial adverse effects on a signal obtained fromthe divided electrode 16 a-3 through the support member 98 a, as thesignals from the divided electrodes 16 a-2 and 16 b-2 cancel each otherby subtracting the signal from the divided electrodes 16 a-2 from thesignal from the divided electrodes 16 b-2.

[0084] In the same way, since the support member 98 a is soldered toboth the divided electrodes 16 a-2 and 16 b-2, the support member 98 bis electrically connected to both the divided electrodes 16 a-4 and 16b-4, and signals output from both the divided electrodes 16 a-4 and 16b-4 are detected though the support member 98 b. However, this also doesnot cause an substantial adverse effect on a signal obtained from thedivided electrode 16 b-3 through the support member 98 b, as the signalsfrom the divided electrodes 16 a-4 and 16 b-4 cancel each other bysubtracting the signal from the divided electrodes 16 a-4 from thesignal from the divided electrodes 16 b-4.

[0085]FIG. 12 shows the vibrating gyroscope 90 mounted on a frame 31.Note that the vibrator 11 shown in FIG. 12 is drawn as a rectangularprism with no electrode for clarity. The vibrator 11 is suspended by thesupport member 98 a to 98 d and placed in the frame 31 made of metal orthe like. The top surface of the frame 31 and the support members 12 a,12 b, 12 d, and 12 f are bonded and secured by soldering or the like. Inthe same manner, the bottom surface of the frame 31 and the supportmembers 12 c and 12 f are fixed. Thus, the vibrator 11 is supported andfixed in the hollow.

[0086] According to the vibrating gyroscope of the fourth embodiment,contact area between the vibrator 11 and the support members 98 a to 98d can be made large due to the expanded portions 99 a to 99 d.Therefore, the adhesive force between the vibrator 11 and the supportmember 98 a to 98 d becomes great, thereby obtaining a sufficient impactresistivity. Moreover, the support members 98 a to 98 d have a thin wirestructure other than the expanded portions 99 a to 99 d. This preventsthe occurrence of damping such as leakage of vibration from the vibrator11 to the outside via the support members 99 a to 99 d, therebyincreasing the amplitude of vibration of the vibrator 11 and improvingthe detection sensitivity.

[0087] In addition, each of the support member has the expanded portionand the pair of bent portions connected to the expanded portion, and theexpanded portion of each support member is fixed at approximately themiddle of the vibrator 11 in the transverse direction thereof. Thus, theimpact applied to the vibrator 11 is transmitted to both ends of theeach support member so that the expanded portion of each support memberis not subjected to severe impact or stress due to impact. Thissuccessfully prevents each support member from being detached from thedivided electrode fixed to each support member.

[0088] In addition, the support members 98 a and 98 b fixed to thesurface where the split electrodes 16 a and 6 b are formed areconfigured to be electrically connected to the divided electrodes 16 a-3and 16 b-3, respectively. Therefore, the support members 98 a and 98 bfirmly support the vibrator 11 while working as lead wires.

[0089]FIG. 13 shows a variation of the vibrating gyroscope according tothe third embodiment of the present invention. A vibrating gyroscope 100shown in FIG. 13 is different from the vibrating gyroscope 90 shown inFIG. 11 in the following features.

[0090] The support member 98 a has another protrusion 98 a″ extendingfrom the expanded portion 99 a toward the divided electrode 16 b-1 inthe direction opposite to the direction in which the protrusion 98 a,extends, and the protrusion 98 a″ is electrically connected to thedivided electrode 16 b-1.

[0091] The support member 98 b also has an another protrusion 98 b″extending from the expanded portion 99 b toward the divided electrode 16a-5 in the direction opposite to the direction in which the protrusion98 b′ extends, and the protrusion 98 b″ is electrically connected to thedivided electrode 16 a-5.

[0092] According to this structure, the divided electrode 16 a-3 and thedivided electrode 16 b-3 are electrically connected to the dividedelectrode 16 b-1 and the divided electrode 16 a-5, respectively so as tobe connected to the divided electrodes located diagonally. Since thesignal generated at the divided electrodes 16 a-1 and 16 b-1 or at thedivided electrodes 16 a-5 and 16 b-5 has the opposite polarity to thatgenerated at the divided electrodes 16 a-3 and 16 b-3, the signalcorresponding to the rotational angular velocity becomes large due tothe sum of the signal from divided electrode 16 a-3 and the signal fromthe divided electrode 16 b-1 and the sum of the signal from dividedelectrode 16 b-3 and the signal from the divided electrode 16 a-5,thereby improving the detection efficiency.

[0093] In this embodiment, the vibrating gyroscope 90 shown in FIG. 11comprises the vibrator 11 provided with the grooves S1, S2, S3 and S4 sothat the signals generated at the divided electrode 16 a-1 and 16 b-1are not used and that the signals generated at the divided electrodes 16a-2 and 16 b-2 in the vicinity of the nodes N1 and N2 are canceled.Since the signals generated in the vicinity of the nodes N1 and N2 arevery weak, this structure reduces the adverse effects due to thecompositional and or dimensional variation of the vibrator 11 andprovides more accurate detection signals.

[0094] In the case where such variations may be negligible, the groovesS1 and S4 may be omitted. In such a case, the signals generated at theoutsides of the nodes N1 and N2 are ideally canceled, and do not affectthe detection of the signal corresponding to the rotational angularvelocity.

[0095] In addition, the support member 98 a to 98 d may be fixed to thevibrator 11 through a non-electroconductive adhesive. In such a case itis possible to omit the grooves S2 and also possible to omit the groovesS2 and S3. Further, the grooves S1 and S4 can be omitted although thesignals output from the split electrode 16 a and 16 bare reduced due tothe fact that the polarity of the signals are inverted between theoutside of the nodes N1 and N2 and the inside of the nodes N1 and N2.

[0096] Moreover, the support member 98 a to 98 d may have a shapedifferent form that shown in FIG. 11 or FIG. 13. Specifically, expandedportions 99 a to 99 d may have a circular shape, a ring shape, or otherpolygonal shape. The expanded portions 99 a to 99 d may be omitted.Further, the bent portion of the support member may have the shape otherthan a Z-shape. For example, the bent portion of the support member mayhave an arch shape. Although it is preferable that the support memberhave a flexible bent portion to support the vibrator elastically, thebent portion may be a straight flexible wire or the like.

[0097] While preferred embodiments of the invention have been disclosed,various modes of carrying out the principles disclosed herein arecontemplated as being within the scope of the following claims.Therefore, it is understood that the scope of the invention is not to belimited except as otherwise set forth in the claims.

What is claimed is:
 1. A vibrating gyroscope, comprising: a vibratorhaving at least one node; and a support member having a thin flexibleportion and an expanded portion which is connected to the thin flexibleportion and has a larger area than the thin flexible portion, theexpanded portion of the support member being fixed to the vibrator atthe at least one node.
 2. A vibrating gyroscope according to claim 1,wherein the expanded portion has a through-hole therein.
 3. A vibratinggyroscope according to claim 1, wherein the thin flexible portion of thesupport member is bent in a z-shape.
 4. A vibrating gyroscope accordingto claim 1, further comprising a frame having an internal hollow spacefor receiving the vibrator, the thin flexible portion of the supportmember being connected to the frame to suspend the vibrator within theinternal hollow space.
 5. A vibrating gyroscope according to claim 1,wherein the vibrator comprises: first and second piezoelectricsubstrates stacked with each other, the first and second piezoelectricsubstrates being polarized in opposite directions of their thicknessdirections; a pair of split electrodes formed on a principal surface ofthe first piezoelectric substrate; and a common electrode formed on aprincipal surface of the second piezoelectric substrate.
 6. A vibratinggyroscope, comprising: a vibrator having at least a first node; andfirst and second support members supporting the vibrator such that thefirst and second support members sandwich the at least first node of thevibrator.
 7. A vibrating gyroscope according to claim 6, wherein each ofthe support members has a thin flexible portion and an expanded portionwhich is connected to the thin flexible portion and has a larger areathan the thin flexible portion, the expanded portion of each supportmember being fixed to the vibrator at opposite sides of the at least onenode.
 8. A vibrating gyroscope according to claim 7, wherein the thinflexible portion of each support member is bent in a z-shape.
 9. Avibrating gyroscope according to claim 6, further comprising a framehaving an internal hollow space for receiving the vibrator, the thinflexible portion of each support member being connected to the frame tosuspend the vibrator within the internal hollow space.
 10. A vibratinggyroscope according to claim 6, wherein the vibrator comprises: firstand second piezoelectric substrates stacked with each other, the firstand second piezoelectric substrates being polarized in oppositedirections of their thickness directions; first and second splitelectrodes formed on a principal surface of the first piezoelectricsubstrate; and a common electrode formed on a principal surface of thesecond piezoelectric substrate.
 11. A vibrating gyroscope according toclaim 10, wherein each of the first and second split electrodes isdivided into at least first and second portions and the expanded portionof each of the first and second support members are attached to thefirst portions of each of the first and second split electrodes, theexpanded portion of the first portion further being electricallyconnected to the first portions of the first split electrode and theexpanded portion of the second support member further being connected tothe second portion of the second split electrode.
 12. A vibratinggyroscope according to claim 10, further comprising third and fourthsupport members, wherein the vibrator has a second node and the thirdand fourth support members support the vibrator such that the third andfourth support members sandwich the second node of the vibrator.
 13. Avibrating gyroscope according to claim 12, wherein each of the first,second third and fourth support members has a thin flexible portion andan expanded portion which is connected to the thin flexible portion andhas a larger area than the thin flexible portion, and each of the first,second third and fourth support members is fixed to the vibrator at theexpanded portion thereof.
 14. A vibrating gyroscope according to claim12, wherein one of the first and second support members is electricallyconnected to the first split electrode and one of the third and fourthsupport members is electrically connected to the second split electrode.15. A vibrating gyroscope according to claim 13, wherein the thinflexible portion of each support member is bent in a z-shape.